1. Field of the Invention
The present invention relates to a rolling mill with laterally different velocities.
2. Discussion of Background
In general, metal workpiece is rolled by passing it between a pair of upper and lower rolls in a rolling mill.
It is known in the art that in rolling operation, to rotate a pair of upper and lower rolls 1 and 2 at different rotational or peripheral velocities as shown in FIG. 28 will cause oppositely directed frictional shearing forces to act on upper and lower surfaces of the workpiece 3 which is being rolled through a roll gap 4. As a result, as compared with a rolling operation with the rolls 1 and 2 rotated at equal velocity, the same rolling draft can be attained with a lower rolling load or a higher rolling draft can be attained with the same rolling load. This is called different peripheral velocity rolling or different velocity rolling and has been widely practiced.
In the different velocity rolling as described above, the greater the difference between peripheral velocities of the rolls 1 and 2 is or the higher the different velocity ratio is, the smaller rolling load is required.
In the different velocity rolling as described above, so-called parallel rolls each having a barrel with axially uniform diameter have been used as said paired rolls 1 and 2, which have no ability of controlling workpiece profile for the purpose of correcting defective profile such as edge, center or quarter buckle. This necessitates some extra means being provided to achieve profile control of the workpiece 3.